Phosphorus-containing triazines

ABSTRACT

NEW PROCESSES FOR PREPARING AMINOALKOXYPHOSPHINYL1,3,5-TRIAZINES AND PROCESSES FOR PRODUCING FLAME RESISTANT CELLULOSIC MATERIALS BY TREATING THE CELLULOSIC MATERIALS WITH THE FORMALDEHYDE DERIVATIVES OF THE AMINOALKOXYPHOSPHINYL TRIAZINES.

Zine-Meme United 3,654,274 PHOSPHORUS-CONTAINING TRIAZINES Leon H.Chance and Jerry P. Moreau, New Orleans, La.,

assignors to the United States of America as represented by theDepartment of Agriculture No Drawing. Filed June 9, 1970-, Ser. No.44,864 Int. Cl. C07d 55/20 US. Cl. 260249.8 2 Claims ABSTRACT OF THEDISCLOSURE New processes for preparing aminoalkoxyphosphinyl-1,3,5-triazines and processes for producing flame resistant cellulosicmaterials by treating the cellulosic materials with the formaldehydederivatives of the aminoalkoxyphosphinyl triazines.

derivatives as fia ne retardant, finishes. for cellulosic textiles. W

The main object of the instant invention is to disclose new methods ofpreparing aminoalkoxyphosphinyl triazmes.

A second object of the instant invention is to provide a process forpreparing the formaldehyde derivatives of the compounds prepared bymethods of the instant invention.

A third object of the instant invention is to provide a process forimparting to cotton and other cellulosic material, improved flameresistance, using the formaldehyde derivatives of the compounds preparedby methods of the instant invention.

Searching the prior art we find that Gaetano F. DAlelio claims to haveprepared aminoalkoxyphosphinyl triazines by the reaction ofchloroamino-triazines with trial-kyl phosphites by way of the well knownArbusov reaction. [Gaetano F. DAlelio, U.S. Pat. 3,011,998, Dec. 5,1961, and U8. Pat. 3,210,350, Oct. 5, 1965.] We were unable to duplicateDAlelios method. When we tried to duplicate DAlelios Example 1 whichstates:

In a suitable reactor equipped with stirrer and reflux condenser amixture of 145.5 parts of 2,4-diamino-6- monochloro-l,3,5 triazine and200 parts of'triethyl phosphite and 200 parts of benzene are heated atreflux for eight hours, at which time no more ethyl chloride is releasedfrom the reactionYFhe reactionis then cooled and the solid 'bon, 28.1%nitrogen, 5.35% hydrogen, and 12.2% phosphorous, and a molecular weightof 246.1, which values are in close agreementwith'the'theoretical'values. When 165 parts of the correspondingmonoamino-dichlorotri- 'azine are'reactedinstead ofthemonoch'lorotriazine with 380 parts of'triethyl phosphite, and thereaction product isolated, there is obtained an almostquantitative yieldof 3,654,274 Patented Apr. 4, 1972 which on analysis gives values of35.16% carbon, 5.89% hydrogen, 15.35% nitrogen, and 17.21% phosphorus,and a molecular weight of 367.1, which values are in close agreementwith the theoretical values. When this diester is allowed to stand atroom temperature with aniline, the corresponding is obtained. Thesecompounds are very effective as fire retardants when impregnated intowood, etc. according to standard methods, and are also effective astanning agents for leather.

When halotriazines of the formula (A) (C N )Cl, or

Zo Nsol or A(C N )Cl are used instead of the halotriazines of thepreceding example, the corresponding triazine derivatives are obtained.These products show very good fire retardant properties We obtained noneof the expected product when either triethyl phosphite or trimethylphosphite was allowed to react with 2,4-diamino-6-chloro-1,3,5-triazine.The latter compound was recovered unchanged in yields up to 92%. We havefound new methods of preparing aminoalkoxyphosphinyl triazines which arean improvement over the methods of the prior art. We have also foundthat it is advantageous to carry out the reaction of formaldehyde withaminoalkoxyphosphinyl triazines under acidic conditions at temperaturesof 95 C. for periods of time less than 30 minutes. When the reaction iscarried out at 859 5 C. for less than 30 minutes condensation of theformaldehyde derivative is minimized, producing a Water soluble furtherpolymerizable product which is suitable for application to cellulosictextiles.

We have found that when the aminoalkoxyphosphinyl triazines are heatedwith alkaline aqueous formaldehyde the solutions become acidic due tohydrolysis. Thus, we were not able to prepare formaldehyde derivativessuitable for cellulose textile application by boiling theaminoalkoxyphosphinyl triazines with aqueous formaldehyde under alkalineconditions as described by DAlelio in Example 2 of U8. Pat. 3,011,998,said example states:

Twenty-one parts of ICI) za( a :)P 0, 02 and 32 parts of aqueousformaldehyde (approximately 37% H-CHO) are heated together with 0.02part of sodium hydroxideunder reflux at the boiling point of 'themixture, ,for 30 minutes, yielding a resinous reaction product thatcuresto an insoluble, infusible mass when a sample is heated on a hotplate at 150C. A satisfactory molding compound that shows adequate flowcharacteristics during molding is produced by mixing a portion of theresinous syrup with a weight of alpha cellulose equal to'the solidscontent of the syrup followed by drying at low temperature to remove theexcess water. A well-cured molded piece is obtained by molding a sampleof the dried and ground molding compound for 3 minutes at C. under apressure of 5000 pounds per square inch. Instead. of heating thereactants under reflux, as described above, the mixture is stirred for alonger period, 72 hours, atroom temperautre to effect reaction betweenthe components and to obtain a soluble, fusible reaction product whichis heathardenable.

Other alkaline condensation catalysts that can be used include sodiumcarbonate, ammonia, triethanol amine, hexamethylene tetramine, etc., andacidic curing catalysts include acetic acid, phthalic acid, ammoniumchloride, ammonium phosphate, glycine, chloroacetamide, chloroacetylurea, etc., or substances which under the influence of the reaction orheat produce such acidic substances.

When instead of 2)2( :s s)- CKHQZ there is used an equivalent amount of(113N028 C6II4NID2C3N3" (O (ll-I9 etc., heat convertible condensationproducts are obtained.

Formaldehyde derivatives prepared by DAlelios method form condensationproducts which make cellulosic materials too stiff and boardy fortextile uses.

Compounds of this invention comprise triazine derivatives of the generalformula: 3 c

H N-( 1 i lP (0) (OR):

where R represents an alkyl radical or a haloalkyl radical, X representsNH or P(O) (OR) where R is an alkyl radical or a haloalkyl radical.

We have found that the compounds of this invention can be prepared bynew improved methods according to the following equations: )2

+HOP(OR) where R represents an alkyl radical or a haloalkyl radical. )2

+2HOP(OR) where R represents an alkyl or a haloalkyl radical.

Specific examples of the reactions of this invention are represented bythe following equations:

I- ZNH:

IITIIz In accordance with the present invention a 2,4,6-tris(dialkoxyphosphinyl) 1,3,5-triazine (represented by Equation 2) or a2-arnino-4,6-bis(dialkoxyphosphinyl)-l,3,5- triazine (represented byEquation 1) is allowed to react with ammonia. Triazines particularlysuitable for the invention are2,4,6-tris(diethoxyphosphinyl)-l,3,5-triazine,2,4,6-tris(dirnethoxphosphinyl) 1,3,5-triazine,2,4,6-tris(fichloroethoxyphenosphinyl)1,3,5triazine, and 2-amino-4,6-bis(diethoxyphosphinyl)-l,3,5-triazine. The preferred compounds are2,4,6-tris(diethoxyphosphinyl)1,3,5-triazine and2-amino-4,6-bis(diethoxyphosphinyl)l,3,5-triazine, Solvents suitable forthe reaction are polar solvents such as water or ethanol and non-polarsolvents such as benzene. While other organic solvents may be used, thepreferred solvent is ethanol.

The reaction of the phosphinyl triazines with ammonia may be carried outat temperature about from 0 C. to 40 C. The reaction is preferablycarried out by dissolving the triazines in the solvent and then addingthe ammonia. The preferred temperature for adding the ammonia is aboutfrom 0 C. to 15 C. After the addition of the ammonia is complete thereaction is allowed to take place at room temperature for about from 24hours to 72 hours. The preferred time is about 72 hours.

Theoretically, 4 moles of formaldehyde can react with one mole of adiaminoalkoxyphosphinyl triazine and 2 moles of formaldehyde can reactwith aminobis(alkoxy-- phosphinyl) triazines. In practice, however, itis advantageous to use formaldehyde in excess of the theoretical amountin order to insure as complete a reaction as possible. A typicalreaction of formaldehyde with a triazine is represented by the followingequation:

It is not likely, however, that a tetramethylol derivative is actuallyproduced in the acidic media employed in the reaction. Apparently, lowmolecular weight water soluble condensation products of the formaldehydederivatives are formed which are capable of polymerizing further tocrosslinked polymers which are insoluble in water and most organicsolvents. The formaldehyde derivaties are preferably formed by mixingthe aminoalkoxyphosphinyl triazine with aqueous formaldehyde in a moleratio of 1:4 to 1:65. The preferable ratio of triazine to formaldehydeis 1:5. The initial pH of the mixture. is 3.3, but at the end of theheating period drops to about from. 2.6 to 3.0. The mixture is thenplaced in a suitable preheated bath and the reaction mixture brought asquickly as possible to 85 95 C. A water bath was used but any suitableheating device may be used. The heating time may be varied about fromminutes to 27 minutes. The preferable time is about from 15 to 17minutes.

After the heating period is completed, the solution is cooled to roomtemperature quickly and adjusted to the desired pH with aqueous sodiumhydroxide for applica' tion to cellulosic materials. Other suitablebases may be.

used.

The polymerization on cellulosic materials may be carried out byimpregnating the cellulosic material with a solution of the further.polymerizable formaldehyde deriva tives, drying, and curing attemperatures ranging about from 150 to 170 C. for periods of time aboutfrom 5 to 7 minutes. Latent acid catalysts such as magnesium chloride orzinc nitrate may be used in the application to cellulosic materials, butit is preferable to use no catalyst.-Tex tile lubricants or softeningagents may be added to the treating baths to improve thestrength andabrasion resistance of the treated textiles. A pad bath pH of 6.5-6.6 ispreferred for best fabric strengthand abrasion resistance and flameresistance.

Cotton fabrics treated by the processes of this invention possess goodflame resistance which is durable to repeated laundering. Fabricstrength and abrasion resistance properties are also good.

Cotton fabrics which have been treated by the processes of thisinvention were tested by the standard methods of the American Societyfor Testing Materials, Philadelphia, Pa., Committee D-13. Wrinklerecovery was determined by the Monsanto Method. AST M designation,Dl295-53T; breaking strength by the one-inch strip method, D39-59;tearing strength by the Elmendorf Method, D1295-60T; flex abrasionresistance by the Stoll Method, D1175-65T. Flame resistance wasdetermined by the standard vertical method, U.S; Federal Supply ServiceTextile Test Methods, Federal Specification CCC-T- 191b, Method 5902.Durability of the flame resistant finish to laundering was determined bywashing in an agitator-type washing machine under normal washingconditions for cotton, using a commercialdetergentaEach laundering cyclewas followed by tumbledryin gfor 2O minutes.

The following examples illustrate the methods of carrying out theinvention, but the inventionis not restricted to these examples. In theexamples the following abbreviations will be used:2,4,6-tris(diethoxyphosphinyl)triazine will be referred to as TEPT;2,4-diamino-6-diethoxyphosphinyl triazine, as DAPT;2-amino-4,6-bis(diethoxyphosphinyl)triazine, as ADPT; the formaledhydederivative DAPT, as N-methylol DAPT or M DAPT.

EXAMPLE 1 2,4-diamino 6 diethoxyphosphinyl triazine (DAPT): DAPT wasprepared by the reaction of TEPT with ammonia in (a) ethanol, (b)benzene, and (c) Water.

Ethanol procedure: 2,4,6-tris(diethoxyphosphinyl)-1,3, S-triazine (TEPT)(97.9 grams, M.P. 93-95 C.) was dissolved in 400 ml. of absoluteethanol. The solution was cooled in an ice-salt bath to approximately 0C., and then saturated with ammonia gas. The addition was regulated sothat the reaction temperature did not rise above 15 C. The solution wasallowed to stand for three days. After cooling, the precipitated whitesolid was removed by filtration, washed thoroughly with water thenacetone and dried to give 41.2 grams (83% yield) of DAPT.

When the above reaction was carried out without cool ing during theammonia addition the temperature rose from 22 to 40 C. in 5-10 minutes.After standing at room temperature for 24 hours, the DAPT was isolatedas above in yields of only 30%. Diethyl hydrogen phosphite was recoveredby vacuum distillation as the major byproduct in 75% yield.

A sample of DAPT, recrystallized from boiling water, had a M.P. of 273C. with decomposition. The IR spectrum showed absorption bands at 2.99,3.12 microns (s.) (NH stretching); 6.00, 6.14 microns (s.) (NHdeformation); 6.46, 6.56 microns (s.) (ring stretching); 8.18 microns(s.) (P=O); 9.77, 13.47 microns (s.) (w.) (POC); and 12.24, 12.59microns (w.) (ring bend ing). The PMR spectrum (DMSO) gave a triplet at4.17 p.p.m. (J =J =7 cps.) and a singlet at 7.00 p.p.m. The spectrumintegrated 3:212, respectively.

Analysis.-Calcd. for C H N O P (percent): C, 34.01; H, 5.71; N, 28.33;P, 12.53. Found (percent): C, 34.00; H, 5.66; N, 28.38; P, 12.60.

Benzene procedure: TEPT (0.023 mole, 11.4 grams) was dissolved in 35 ml.of benzene, the solution cooled and then saturated with ammonia. Aftercooling overnight, the white precipitate was removed by filtration togive 0.93 gram (0.004 mole, 17.4% yield) of DAPT. The filtrate wasconcentrated and diethyl hydrogen phos phite (0.022 moles, 3.1 grams)removed by vacuum dis= tillation. The residue, which solidifiedovernight, was triturated in petroleum ether, filtered and dried to give6.21 grams of a white crystalline compound. A sample of this compound,after recrystallization from diethyl ether, had elemental analyses andmelting point consistent with an authentic sample of2-amino-4,6-bisdiethoxyphosphinyl-1,3,5-triazine (ADPT) as prepared byDAlelio [U. S. Pat. 3,210,350 (1965)]. This constitutes a new method forpreparing ADPT.

Water procedure: TEPT (0.05 mole, 24.5 grams) was added in' incrementsto 75.5 grams of NH; (28% NH;;). The reaction temperature rosespontaneously to 34 C. After standing at room temperature for five days,the white precipitate was removed by filtration, washed thoroughly withwater then acetone and dried to give 2.11 grams (0.009 mole,'18% yield)of DAPT.

EXAMPLE 2 DAPT was also prepared by the ethanol procedure described inExample 1 except that ADPT was used instead of TEPT. (see Equation 5 ofspecification.)

EXAMPLE 3 Preparation of N-methylol DAPT (MDAPT) MDAPT was prepared bythe following typical pro cedure, DAPT (49.4 g., 0.2 mole), formaldehyde(83.0

g. of 36.6% HCHO, 1.0 mole), and water (43.0 g.) were placed in a 300ml. flask equipped with a reflux con denser, stirrer, and thermometer(immersed in the liquid). This was a mole ratio of DAPTzHCHO of 1:5. Theflask was immersed in a water bath which had been preheated to boiling.After approximately minutes of heating and stirring, the DAPT dissolvedcompletely forming a clear solution. At this point the solutiontemperature was about 9495 C. Heating and stirring at this temperaturewere continued for an additional 6 minutes, for a total heating time ofabout 16 minutes. If possible, the total heating time should not exceed16 minutes. If the solution is heated too long, excessive condensationof MDAPT apparently occurs. Even under the conditions described, it isbelieved that some condensation occurs, but the prod uct is of lowmolecular weight and hence very water soluble.

After the heating was completed, the flask was immediately cooled byimmersing the flask in cold water. The pH of the resulting solution was2.7. The solution was adjusted to the desired pH with sodium hydroxidesolution and served as a stock solution.

In one experiment crude MDAPT was isolated as a clear colorless, veryviscous material by evaporation of the water under high vacuum at about50 C. This material was not as stable upon storage as the watersolution, and set to a gel in two or three weeks.

Analysis.Calculated for C H N O P (percent) (tetramethylol derivative ofDAPT): C, 35.97; H, 6.04; N, 19.07; P, 8.43. Found (percent): C, 37.68;H, 6.44; N, 18.29; P, 8.29.

Solutions of the formaldehyde derivatives of DAPT were also prepared ina similar manner as above in which the heating time was varied from 15minutes to 27 minutes. Heating periods of 16-17 minutes were consideredoptimum. Temperatures as low as 85 C. were used for heating periodsabove 20 minutes.

Solutions were also prepared in a similar manner in which the DAPT toformaldehyde ratio was 1:4 and 1:6. When the ratio was 1:4 a longerheating period minutes) was needed to solubilize the DAPT.

EXAMPLE 4 Fabric treatment with MDAPT The fabric used in the experimentswas an 8.5 oz. white cotton sateen.

The stock solutions prepared as described above are stable for severaldays without any loss of efliciency when applied to cotton fabric. (Asolution stored for 2 months at room temperature [27 C.] did not get,and when applied to cotton fabric had an efficiency 1718% less than afreshly prepared solution.) The pH of the solutions shifts downwardduring storage. Therefore, it is necessary to adjust to the desired pHjust prior to treating cotton fabrics. All of the pad baths used in thisreport contained 0.1% wetting agent and 1.5% softener (dry solidsbasis). The solution as prepared above, after addition of the wettingagent and softener, contained approximately 27% DAPT (or MDAPTcalculated as the tetramethylol derivatives). These values were based onthe total weight of the solution. Just prior to fabric treatment, thesolution was diluted to the desired concentration, and finally adjustedto the desired pH with aqueous sodium hydroxide solution.

In some of the experiments, magnesium chloride hexahydrate was used as acatalyst. The percent catalyst (as the hexahydrate) was based on thetotal weight of the solution as it was applied to the fabrics.

The solutions were applied to the fabrics by padding procedures to givea wet pickup of about 80% on sateen. The fabrics were dried for 5minutes at 85 C. and cured for 37 minutes at temperatures ranging from150 C. 170 C. The fabrics were finally rinsed in hot water and dried.

Table I shows the properties of white 8 oz. cotton sateen containingpolymer add-ons of 14.7%, 17.6%, and 19.5%.

These add-ons were obtained by using pad bath concentrationsapproximately 20%, 24%, and 27%, respectively, based on actual DAPTcontent. The ratio of DAPT to formaldehyde in the pad baths was 1:5. Thefabrics were dried for 5 minutes at C. and cured for 7 minutes at 160 C.

TABLE I.-PIIYSICAL PROPERTIES OF COTTON SATEEN Resin add-on, percentUntreated Fabric properties control 14. 7 17. 6 19. 5

Phosphorus, percent 1. 70 1. 76 1.86 Nitrogen, percent... 3. 46 3. 61 4.00 Char length, inches... 3. 1 3. 4 3. 1 Flex abrasion (F), cycles.. 1,505 .2, 215 2,264 Tear strength (F), gms... 3,400 3,400 3,107 Breakingstrength (F), lbs 84. 4 80. l 82. 5

The fabric samples shown in Table I were subjected to repeatedlaundering cycles followed by tumble drying. The flame resistance asmeasured by char length in the standard vertical flame test were asfollows: at 14.7% add-on the char length was 5.3 inches after 15launderings; at the 17.6% add-on the char length was 5.0 inches after 30launderings; and at the 19.5% add-on the char length was 5.5 inchesafter 35 launderings.

EXAMPLE 5 Add-on=weight gain of cotton after curing and rinsing Wetpickup=weight of cotton+solution before drying DAPT conc.=concentrationof DAPT in pad bath TABLE II.-INFLUENCE OF MOLE RATIO OF DAP'IzIIClIOPad bath eone., per- Resin add- Etficiency, Mole ratio, DAPTzHCHO centDAPT on, percent percent No'rE.Sateen fabric; dried 5 min. at 85 0.,cured 7 min. at C EXAMPLE 6 Table III shows the influence of curing timeon the resin add-on and efficiency. They increase with increasingtemperature.

TABLE IIL-INFLUENCE OF CURING TEMPERATURE Resin add-on Etliciency(luring tein1)., C. percent percent.

EXAMPLE 7 Table IV shows the influence of curing time on some fabricproperties. Highest add-on and flame resistance are obtained at the 7minute cure time.

TABLE IV.INFLUENCE OF CURING TIME l lex abrasion Resin Efli- Char addon,ciency, length, (W), Curing time, min. percent percent warp cycles (F),irls 3 7. 7 51 2 BEL 2, 800

12.2 81 5. 1 2,020 4,800 7. 14.0 02 4.0 1,136 3,000 Control. 833

1 Over capacity of machine. 2 J3EL=bnrned entire length. Norm-"Sateenfabric; pad bath c0110., 20% DAPT cure tciup., 100

9 10 EXAMPLE 8 We claim: l

Table V shows the influence of pad bath pH on some Process prepgrmgfabric properties. Although higher add-ons were obtained phosp h1r.1y11.35'tnaZme i 9 process fii 3 5 at pH values of 3.0 and 4.5 the strengthlosses were (a) ls.solving msmlethoxyphosphmy excessive. of 6.6 Wasconsidered optimum for flame 5 tnazme m a Solvent Selected from t 6group consisting of ethyl alcohol and benzene, (b) cooling the solutionfrom (a) and saturating with ammonia gas,

resistance versus strength and abrasion resistance.

TABLE V.INFLUENCE ON PAD BATH pH R Abrasion Tearing (c) allowing thereaction mixture from (b) to stand S I Pad bath pH on j p r iit 523? 10fgi ggig zgg fi gg z hours at a tempera $35 3 2? (d) mechanicallyremoving the 2,4 diaminoethoxy- 1,150 5, phosphinyl-1,3,5-triazine.

Q88; 2. A process for preparing2,4-diamino-6-diethoxyphosp-hinyl-1,3,5-triazine which processcomprises: EXAMPLE 9 (a) dissolving 2 amino 4,6bis(diethoxyphosphinyl)l,3,5-triaz ine in ethanol, (b) cooling thesolution from (a) and saturating with ammonium gas, (c) allowing thereaction mixture from (b) to stand for a period of about 24 to 72 hoursat a temperature of not more than 15 C Table VI shows a comparison offabric properties resulting from treatments in which no catalyst wasused with those in which magnesium chloride was used. It is clear thatthe best strength and abrasion properties are obtained with no catalyst.The only advantage in using the catalyst is that slightly higher wrinklerecovery is (d) mechanically removing the 2,4 diaminoethoxy obtained.phosphinyl-1,3,5-triazine.

TABLE VI.-INFLUENCE OF CATALYST, MgClgfiHgO Wrinkle re) R Eir- T B k A yMECIQ-GI'IZO, add iif ciency streng t li sisting t ii res is t afi i c edifi j percent percent percent (F), gms. (W), lbs. (W), cycles degrees 114. 5 94 3, 4.00 84. 4 1,136 238 10.8 70 2, s33 68. 1 601 254 10. 9 722, 500 65. 0 478 249 11.7 76 2, 317 60. 9 347 25 1 14.1 94 1, 617 48. 2138 258 Control 5, 300 105. 0 833 173 1 Cured 7 min. at 160 C.Norm-Sateen fabric; pad bath conc., 20% DAPI; cured 5 min. at 150 0.

EXAMPLE 10 40 References Cited A typical procedure for preparing aformulation for UNITED STATES PATENTS application to cotton fabric using2-amino-bis(diethoxy- 3,165 513 1/1965 DAlelio 2 .249 8 Xphosphinyl)triazine (ADPT) consisted of (l) refluxing 3,210,350 1O/1965DAlelio 249 X ADPT in aqueous formaldehyde (mole ratio 1:2) for 303,2133) 10/1965 Papp et 49 g minutes, (2) adding a softening agent and awetting agent, and "(3) adding trimethylolrnelamine (TMM) (mole ratio ofTMM:ADPT of 2:1) previously dissolved in Water, and (4) diluting to 40%reactive solids (total Weight ADPT, HCHO, and TMM). White 8 oz. cottonsateen was padded to approximately wet pickup, 50 dried for 5 minutes atC., and cured for 7 minutes 8 at C. After rinsing and drying, the weightgain of the fabric was 20%. The fabric had good flame resistance asdetermined by a char length of 2.7 inches.

45 3,305,348 2/1967 Schwarze et a1. 260249.8 X

JOHN M. FORD, Primary Examiner US. Cl. X.R.

116.3; 106l5 FP; l17l36; 2528.8; 260249.5

